https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101464
Bug ID: 101464 Summary: Replace zveroupper with vpxor Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: hjl.tools at gmail dot com Target Milestone: --- Target: i386, x86-64 [hjl@gnu-cfl-2 pr101456]$ cat y.c #include <x86intrin.h> extern __m256d x, y; void foo (void) { x = y; } [hjl@gnu-cfl-2 pr101456]$ gcc -S -O2 -mavx2 y.c [hjl@gnu-cfl-2 pr101456]$ cat y.s .file "y.c" .text .p2align 4 .globl foo .type foo, @function foo: .LFB5667: .cfi_startproc vmovapd y(%rip), %ymm0 vmovapd %ymm0, x(%rip) vzeroupper ret .cfi_endproc .LFE5667: .size foo, .-foo .ident "GCC: (GNU) 11.1.1 20210531 (Red Hat 11.1.1-3)" .section .note.GNU-stack,"",@progbits [hjl@gnu-cfl-2 pr101456]$ vzeroupper can be replaced by a single pxor.